drm/mm: fixup typo in debug functions.
[linux-2.6.git] / drivers / gpu / drm / drm_mm.c
1 /**************************************************************************
2  *
3  * Copyright 2006 Tungsten Graphics, Inc., Bismarck, ND., USA.
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
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11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
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14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
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26  *
27  **************************************************************************/
28
29 /*
30  * Generic simple memory manager implementation. Intended to be used as a base
31  * class implementation for more advanced memory managers.
32  *
33  * Note that the algorithm used is quite simple and there might be substantial
34  * performance gains if a smarter free list is implemented. Currently it is just an
35  * unordered stack of free regions. This could easily be improved if an RB-tree
36  * is used instead. At least if we expect heavy fragmentation.
37  *
38  * Aligned allocations can also see improvement.
39  *
40  * Authors:
41  * Thomas Hellström <thomas-at-tungstengraphics-dot-com>
42  */
43
44 #include "drmP.h"
45 #include "drm_mm.h"
46 #include <linux/slab.h>
47 #include <linux/seq_file.h>
48
49 #define MM_UNUSED_TARGET 4
50
51 unsigned long drm_mm_tail_space(struct drm_mm *mm)
52 {
53         struct list_head *tail_node;
54         struct drm_mm_node *entry;
55
56         tail_node = mm->ml_entry.prev;
57         entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
58         if (!entry->free)
59                 return 0;
60
61         return entry->size;
62 }
63
64 int drm_mm_remove_space_from_tail(struct drm_mm *mm, unsigned long size)
65 {
66         struct list_head *tail_node;
67         struct drm_mm_node *entry;
68
69         tail_node = mm->ml_entry.prev;
70         entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
71         if (!entry->free)
72                 return -ENOMEM;
73
74         if (entry->size <= size)
75                 return -ENOMEM;
76
77         entry->size -= size;
78         return 0;
79 }
80
81 static struct drm_mm_node *drm_mm_kmalloc(struct drm_mm *mm, int atomic)
82 {
83         struct drm_mm_node *child;
84
85         if (atomic)
86                 child = kmalloc(sizeof(*child), GFP_ATOMIC);
87         else
88                 child = kmalloc(sizeof(*child), GFP_KERNEL);
89
90         if (unlikely(child == NULL)) {
91                 spin_lock(&mm->unused_lock);
92                 if (list_empty(&mm->unused_nodes))
93                         child = NULL;
94                 else {
95                         child =
96                             list_entry(mm->unused_nodes.next,
97                                        struct drm_mm_node, fl_entry);
98                         list_del(&child->fl_entry);
99                         --mm->num_unused;
100                 }
101                 spin_unlock(&mm->unused_lock);
102         }
103         return child;
104 }
105
106 int drm_mm_pre_get(struct drm_mm *mm)
107 {
108         struct drm_mm_node *node;
109
110         spin_lock(&mm->unused_lock);
111         while (mm->num_unused < MM_UNUSED_TARGET) {
112                 spin_unlock(&mm->unused_lock);
113                 node = kmalloc(sizeof(*node), GFP_KERNEL);
114                 spin_lock(&mm->unused_lock);
115
116                 if (unlikely(node == NULL)) {
117                         int ret = (mm->num_unused < 2) ? -ENOMEM : 0;
118                         spin_unlock(&mm->unused_lock);
119                         return ret;
120                 }
121                 ++mm->num_unused;
122                 list_add_tail(&node->fl_entry, &mm->unused_nodes);
123         }
124         spin_unlock(&mm->unused_lock);
125         return 0;
126 }
127 EXPORT_SYMBOL(drm_mm_pre_get);
128
129 static int drm_mm_create_tail_node(struct drm_mm *mm,
130                                    unsigned long start,
131                                    unsigned long size, int atomic)
132 {
133         struct drm_mm_node *child;
134
135         child = drm_mm_kmalloc(mm, atomic);
136         if (unlikely(child == NULL))
137                 return -ENOMEM;
138
139         child->free = 1;
140         child->size = size;
141         child->start = start;
142         child->mm = mm;
143
144         list_add_tail(&child->ml_entry, &mm->ml_entry);
145         list_add_tail(&child->fl_entry, &mm->fl_entry);
146
147         return 0;
148 }
149
150 int drm_mm_add_space_to_tail(struct drm_mm *mm, unsigned long size, int atomic)
151 {
152         struct list_head *tail_node;
153         struct drm_mm_node *entry;
154
155         tail_node = mm->ml_entry.prev;
156         entry = list_entry(tail_node, struct drm_mm_node, ml_entry);
157         if (!entry->free) {
158                 return drm_mm_create_tail_node(mm, entry->start + entry->size,
159                                                size, atomic);
160         }
161         entry->size += size;
162         return 0;
163 }
164
165 static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
166                                                  unsigned long size,
167                                                  int atomic)
168 {
169         struct drm_mm_node *child;
170
171         child = drm_mm_kmalloc(parent->mm, atomic);
172         if (unlikely(child == NULL))
173                 return NULL;
174
175         INIT_LIST_HEAD(&child->fl_entry);
176
177         child->free = 0;
178         child->size = size;
179         child->start = parent->start;
180         child->mm = parent->mm;
181
182         list_add_tail(&child->ml_entry, &parent->ml_entry);
183         INIT_LIST_HEAD(&child->fl_entry);
184
185         parent->size -= size;
186         parent->start += size;
187         return child;
188 }
189
190
191 struct drm_mm_node *drm_mm_get_block_generic(struct drm_mm_node *node,
192                                              unsigned long size,
193                                              unsigned alignment,
194                                              int atomic)
195 {
196
197         struct drm_mm_node *align_splitoff = NULL;
198         unsigned tmp = 0;
199
200         if (alignment)
201                 tmp = node->start % alignment;
202
203         if (tmp) {
204                 align_splitoff =
205                     drm_mm_split_at_start(node, alignment - tmp, atomic);
206                 if (unlikely(align_splitoff == NULL))
207                         return NULL;
208         }
209
210         if (node->size == size) {
211                 list_del_init(&node->fl_entry);
212                 node->free = 0;
213         } else {
214                 node = drm_mm_split_at_start(node, size, atomic);
215         }
216
217         if (align_splitoff)
218                 drm_mm_put_block(align_splitoff);
219
220         return node;
221 }
222 EXPORT_SYMBOL(drm_mm_get_block_generic);
223
224 /*
225  * Put a block. Merge with the previous and / or next block if they are free.
226  * Otherwise add to the free stack.
227  */
228
229 void drm_mm_put_block(struct drm_mm_node *cur)
230 {
231
232         struct drm_mm *mm = cur->mm;
233         struct list_head *cur_head = &cur->ml_entry;
234         struct list_head *root_head = &mm->ml_entry;
235         struct drm_mm_node *prev_node = NULL;
236         struct drm_mm_node *next_node;
237
238         int merged = 0;
239
240         if (cur_head->prev != root_head) {
241                 prev_node =
242                     list_entry(cur_head->prev, struct drm_mm_node, ml_entry);
243                 if (prev_node->free) {
244                         prev_node->size += cur->size;
245                         merged = 1;
246                 }
247         }
248         if (cur_head->next != root_head) {
249                 next_node =
250                     list_entry(cur_head->next, struct drm_mm_node, ml_entry);
251                 if (next_node->free) {
252                         if (merged) {
253                                 prev_node->size += next_node->size;
254                                 list_del(&next_node->ml_entry);
255                                 list_del(&next_node->fl_entry);
256                                 if (mm->num_unused < MM_UNUSED_TARGET) {
257                                         list_add(&next_node->fl_entry,
258                                                  &mm->unused_nodes);
259                                         ++mm->num_unused;
260                                 } else
261                                         kfree(next_node);
262                         } else {
263                                 next_node->size += cur->size;
264                                 next_node->start = cur->start;
265                                 merged = 1;
266                         }
267                 }
268         }
269         if (!merged) {
270                 cur->free = 1;
271                 list_add(&cur->fl_entry, &mm->fl_entry);
272         } else {
273                 list_del(&cur->ml_entry);
274                 if (mm->num_unused < MM_UNUSED_TARGET) {
275                         list_add(&cur->fl_entry, &mm->unused_nodes);
276                         ++mm->num_unused;
277                 } else
278                         kfree(cur);
279         }
280 }
281
282 EXPORT_SYMBOL(drm_mm_put_block);
283
284 struct drm_mm_node *drm_mm_search_free(const struct drm_mm *mm,
285                                        unsigned long size,
286                                        unsigned alignment, int best_match)
287 {
288         struct list_head *list;
289         const struct list_head *free_stack = &mm->fl_entry;
290         struct drm_mm_node *entry;
291         struct drm_mm_node *best;
292         unsigned long best_size;
293         unsigned wasted;
294
295         best = NULL;
296         best_size = ~0UL;
297
298         list_for_each(list, free_stack) {
299                 entry = list_entry(list, struct drm_mm_node, fl_entry);
300                 wasted = 0;
301
302                 if (entry->size < size)
303                         continue;
304
305                 if (alignment) {
306                         register unsigned tmp = entry->start % alignment;
307                         if (tmp)
308                                 wasted += alignment - tmp;
309                 }
310
311                 if (entry->size >= size + wasted) {
312                         if (!best_match)
313                                 return entry;
314                         if (size < best_size) {
315                                 best = entry;
316                                 best_size = entry->size;
317                         }
318                 }
319         }
320
321         return best;
322 }
323 EXPORT_SYMBOL(drm_mm_search_free);
324
325 int drm_mm_clean(struct drm_mm * mm)
326 {
327         struct list_head *head = &mm->ml_entry;
328
329         return (head->next->next == head);
330 }
331 EXPORT_SYMBOL(drm_mm_clean);
332
333 int drm_mm_init(struct drm_mm * mm, unsigned long start, unsigned long size)
334 {
335         INIT_LIST_HEAD(&mm->ml_entry);
336         INIT_LIST_HEAD(&mm->fl_entry);
337         INIT_LIST_HEAD(&mm->unused_nodes);
338         mm->num_unused = 0;
339         spin_lock_init(&mm->unused_lock);
340
341         return drm_mm_create_tail_node(mm, start, size, 0);
342 }
343 EXPORT_SYMBOL(drm_mm_init);
344
345 void drm_mm_takedown(struct drm_mm * mm)
346 {
347         struct list_head *bnode = mm->fl_entry.next;
348         struct drm_mm_node *entry;
349         struct drm_mm_node *next;
350
351         entry = list_entry(bnode, struct drm_mm_node, fl_entry);
352
353         if (entry->ml_entry.next != &mm->ml_entry ||
354             entry->fl_entry.next != &mm->fl_entry) {
355                 DRM_ERROR("Memory manager not clean. Delaying takedown\n");
356                 return;
357         }
358
359         list_del(&entry->fl_entry);
360         list_del(&entry->ml_entry);
361         kfree(entry);
362
363         spin_lock(&mm->unused_lock);
364         list_for_each_entry_safe(entry, next, &mm->unused_nodes, fl_entry) {
365                 list_del(&entry->fl_entry);
366                 kfree(entry);
367                 --mm->num_unused;
368         }
369         spin_unlock(&mm->unused_lock);
370
371         BUG_ON(mm->num_unused != 0);
372 }
373 EXPORT_SYMBOL(drm_mm_takedown);
374
375 #if defined(CONFIG_DEBUG_FS)
376 int drm_mm_dump_table(struct seq_file *m, struct drm_mm *mm)
377 {
378         struct drm_mm_node *entry;
379         int total_used = 0, total_free = 0, total = 0;
380
381         list_for_each_entry(entry, &mm->ml_entry, ml_entry) {
382                 seq_printf(m, "0x%08lx-0x%08lx: 0x%08lx: %s\n", entry->start, entry->start + entry->size, entry->size, entry->free ? "free" : "used");
383                 total += entry->size;
384                 if (entry->free)
385                         total_free += entry->size;
386                 else
387                         total_used += entry->size;
388         }
389         seq_printf(m, "total: %d, used %d free %d\n", total, total_used, total_free);
390         return 0;
391 }
392 EXPORT_SYMBOL(drm_mm_dump_table);
393 #endif